Collaborative Research: Algal Food Quality: Its Biochemi- cal Charcterization and Role in Zooplankton Feeding and Fecundity Responses

本研究探讨了影响食草动物取食和繁殖力的藻类食物质量的具体方面。虽然藻类的生理状况是影响摄食率和繁殖的关键因素，但藻类的生化成分往往无法表征或控制。为了验证藻类的主要细胞成分随不同的限制资源（氮、磷、硅、光）而变化的假设，pi将评估在不同资源限制下连续培养的三种藻类在一定生长速率范围内的生化成分模式。为了测试藻类的生化成分是否会影响食草动物的取食率和繁殖率，pi将测量水蚤在不同饲料下的繁殖力。为了评估脂质产生的季节性变化是否反映了浮游植物质量的变化，pi将监测三个湖泊中藻类和浮游动物脂质在营养梯度上的季节性波动。水生生态系统中的食品质量是高度动态的。目的是确定藻类和食草动物适应可变资源基础的一般模式。

The research investigates the specific aspects of algal food quality that affect feeding and fecundity of herbivores. While the physiological condition of the algae is a critical factor influencing ingestion rates and reproduction, biochemical components of the algae are frequently not characterized or controlled. To test the hypothesis that the major cellular constituents of algae vary with different limiting resources (N, P, Si, light), the PIs will assess patterns of biochemical components over a range of growth rates in three species of algae grown in continuous cultures, under various resource limitations. To test whether algal biochemical composition affects the feeding and reproductive rates of herbivores, the PIs will measure fecundity of Daphnia pulicaria with the various diets. To assess if seasonal variation in lipid production reflects changes in the quality of phytoplankton, the PIs will monitor seasonal fluctuations of lipids in algae and zooplankton in three lakes across a trophic gradient. Food quality in aquatic ecosystems is highly dynamic. The aim is to identify the general patterns of accommodation of algae and herbivores to the variable resource base.